This post is co-created with OrxaGrid to showcase OrxaGrid’s interactive & intuitive Single Line Diagram which allows users to easily create, edit and export their single line diagrams
The Grid Analytics Platform features an editable and configurable Single Line Diagram (SLD) tool that brings live system monitoring data from on-site sensors. Having an SLD tool that shows power system data in real-time is useful for substation operators, field engineers and energy managers.
First of All, What is SLD?
In power engineering, a single–line diagram (SLD), also sometimes called a one-line diagram, is a simplified notation for representing a three-phase power system. It is a form of block diagram graphically depicting the paths for power flow between entities of the system.
SLDs are common globally and pretty much all electrical engineers use the same standard schematic symbols to represent the different electricity component networks such as circuit breakers, transformers, capacitors, bus bars, and conductors.
What challenge are we addressing with the SLD maker?
While working with partners installing and monitoring devices on the medium to low voltage network, we were surprised to see how analogue global practices still are. It is still not uncommon for utility companies to have their distribution network live only on datasheet plates, paper documents or excel files.
If data around the network was digitised, it was typically in an inflexible system that could not be exported or combined with real-time data- the data couldn’t be mapped in a visual way.
How big is this Problem?
If utility and distribution network managers only had to maintain a handful of substations, using excel sheets would not be such a big issue. But medium and low voltage substations are ubiquitous, found about 150-200 metres apart in a typical urban area. That means that our clients maintain thousands of medium and low voltage substations in their networks.
Then why haven’t most SLDs been digitised yet?
This is where the predicament comes – because these substations are so numerous, a single substation is considered a “non-critical” energy system component when compared to their high value, high voltage counterparts.
Now consider that the utility relies on legacy systems designed for a small number of high-value assets, making it cost-prohibitive to include thousands of additional assets and their SLDs.
Finally, let’s add that legacy systems make it difficult to export data, which means that uploading all that data will not be a one-time effort that could be shared across systems.
All these factors made digitisation, a monumental and highly unappetising task with little promise for a real return on investment. Any sensible business would avoid taking the time and effort to upload all of this information.
OrxaGrid Solution: The SLD Viewer
Our utility clients expressed a need for a tool that would allow them to digitise their real-time energy network data in a dynamic way. They knew that having their data in a standardised and usable format was key to enabling employees and stakeholders to continue to drive value and benefit from their energy data to get more efficiency from their network and to prevent breakdowns.
Hence, we set out to include an SLD Viewer in the Grid Analytics Platform (GAP) that gave a complete and consolidated view of network assets and connectivity in real-time.
We started by creating a digitised version of each SLD using an SVG file and integrating it with APIs to show live data from our IoT devices. Manually creating an SVG file was a manual and skilled task that could take up to 8 man-hours with back and forth work between both an energy system engineer and our own developers. When used with OrxaGrid’s monitoring devices or SCADA system, the SLD viewer can show users key metrics across their distribution network in real-time.
It wasn’t perfect, but the SLD Viewer looked good and proved to be useful. It became easy for engineers to remotely spot closed and open circuits or to identify an unbalanced load which may damage transformers. It also simplified feeder benchmarking, power transformer maximum permissible load and impact analysis of distributed energy resources on substations. Because it is a web-based application, it didn’t require users to download or install any special software to access their SLD.
The SLD Editor
But as we grew, we started getting far more requests to create new SLDs from utility clients – so we set out to develop a self-service tool that made it quick and easy for system engineers to create, manage, share, update and export their own SLDs. We needed an SLD Editor that allowed for the creation of SVG files that can easily be exported as an XML file.
If we break down an SLD, it is just a collection of a variety of assets arranged in a unique fashion with a special relationship with each of the other assets. If there was an easy and intuitive way a user could drag and drop those elements on an image space that should be sufficient.
Our SLD Editor does exactly that. It allows user to drag, drop and arrange different SLD components such as lines, busbars, circuit breakers, isolators, etc. from a predefined symbol library to create a digital version of SLD that engineers usually draw on paper.
The symbol library is customisable so we can include a new set of symbols to create SLDs as per different standards a company/customer follows, e.g. IEEE / IEC. Similarly, we can also add graphical images in .png format to the SLD if required
After an SLD is created, the user can also link symbol components to real assets (e.g. breaker) in the system which can hold the streaming measurement and status data associated with the asset. Labels can also be added to show static info. The editor allows flexibility to display only the required live parameters as per customers need/priority.
The user can configure the symbol components to display live parameters from their smart devices such as voltage, current, power etc. We can also add digital status such as breaker position, relay operation status, isolator status, etc. Other analogue information can also be mapped to the symbol component such as battery voltage & current, transformer oil and winding temperature, etc. Live values of configured parameters can then be shown along with the SLD symbol in the analytics platform.
So we decided to create a tool that made it easy to manage, update and export data. The SLD files are created using an SLD Editor and can easily be exported as an XML file if needed to share with other software systems.
We are excited to incorporate new features into our SLD editor tool. Here is a list of new features we will be releasing very shortly:
Configurable Symbol Library: we are shortly releasing a symbol uploader functionality to the Editor to increase the freedom of the user to create custom symbols of their choosing. Since it’s a web-based application user need not download/install any special software.
Asset Controlling through SLD: in this release, the user will be able to remotely control their assets using the SLD. This feature will incorporate advanced functionalities such as Select-Before-Operate, Direct Control, Interlocking Logic creation and so on.
Customised Colouring of SLD Components: in this release, the user will be able to create custom colours for SLD components such as choosing different colours for the HV and LV busses. In this release, the user will also be able to define logic based colouring such as changing the HV bus colour if it is in an overloaded condition.
When used with OrxaGrid’s monitoring devices or SCADA system, the SLD maker can show users key metrics across their distribution network in real-time. This means that our customers have the confidence and investing in digitising their network data in a format and data structure that is highly flexible and that can be used in novel ways. Our customers will have the confidence and investing in digitising their network data in a format and data structure that is highly flexible and that can be used in novel ways.